In the newspaper articles they make references to the research. For Example in the first paper from 1975 it is Paul R Erlich who is the researcher.
If you want, you can track down the paper. It may be difficult though.
Edit:
In 1968, Dr. Paul R. Ehrlich wrote a well-publicized book entitled The Population Bomb . Ehrlich predicted widespread famine and disaster unless population growth was reduced to zero in America and throughout the world by compulsory methods if necessary.
If you want, you can track down the paper. It may be difficult though.
Edit: In 1968, Dr. Paul R. Ehrlich wrote a well-publicized book entitled The Population Bomb . Ehrlich predicted widespread famine and disaster unless population growth was reduced to zero in America and throughout the world by compulsory methods if necessary.
Edit: https://science.sciencemag.org/content/173/3992/138.abstract